Biogeochemical and sediment characteristics of streambanks with and without preferential groundwater discharge in the Farmington River Watershed, CT, USA

We performed thermal infrared surveys to locate thermal anomilies,
indicative of preferential groundwater discharge, along exposed
streambanks in three stream reaches within the Farmington River watershed
(northwestern CT and southwestern MA, USA). Our sites include 1) the River
Island reach, a section of the 5th order Farmington River, 2)
West Branch Salmon Brook, a 3rd order tributary to the Farmington River,
and 3) Stratton Brook, a 2nd order tributary to the Farmington River. Once
areas of preferential groundwater discharge were located, we performed
sediment-to-atmosphere greenhouse gas flux measurements and collected
groundwater and sediment samples. In addition, we performed
sediment-to-atmosphere greenhouse gas flux measurements and collected
sediment samples from adjacent streambanks without preferential
groundwater discharge. Surface water samples at each of the three stream
reaches were also collected. Data collected include greenhouse gas fluxes
(CO2, CH4, and N2O), sediment organic matter, groundwater and surface
water chemistry (CO2, CH4, and N2O concentrations, dissolved organic
carbon, dissolved oxygen, total dissolved nitrogen, specific conductance,
NO3-_N), and groundwater and surface water temperature.